Five-year Incidence Trends and the Status of Major Rare Diseases in 2023 in the 「Annual Report on the Rare Disease Patients in Korea」.

Objectives: This study analyzed 5-year trends in rare disease incidence, deaths, and medical expenditures in the Republic of Korea using the 「Annual Report on the Rare Disease Patients in Korea」 (the Annual Report), with particular attention to the 2023 incidence figures by age, province, and frequently occurring diseases. Methods: This retrospective descriptive study used data from the Annual Report from 2019 to 2023. The annual numbers of newly registered rare disease cases and of deaths and the figures for healthcare utilization were analyzed, with particular attention to the incidence status in 2023. Results: Newly registered rare disease cases remained at around 50,000 annually before rising to 62,420 in 2023, with deaths and medical expenditures also increasing. In 2023, the incidence was highest among individuals in their 60s and those in the Gyeonggi-do region. Idiopathic pulmonary fibrosis and systemic lupus erythematosus with organ or system involvement were the most common rare diseases among males and females, respectively. Crohn's disease of the small and large intestine was the most frequent among those in their 10s and 20s, autosomal dominant polycystic kidney disease among those in their 30s to 50s, and idiopathic pulmonary fibrosis among those aged 60 and older, which last also incurred the highest total annual medical expenditure. Conclusions: The Annual Report has enhanced analytical accuracy and comprehensiveness through data refinement and statistical expansion. Future efforts should be directed to a transition from incidence-centered statistics to the establishment of a longitudinal data infrastructure that records incidence rates, survival rates, and the overall prevalence of rare diseases.